bsd-mailx (version 8.1.2-0.20090911cvs-2ubuntu1.1) will be installed
dovecot-common (version 1:1.2.9-1ubuntu6.6) will be installed
dovecot-imapd (version 1:1.2.9-1ubuntu6.6) will be installed
dovecot-pop3d (version 1:1.2.9-1ubuntu6.6) will be installed
libmysqlclient16 (version 5.1.73-0ubuntu0.10.04.1) will be installed
libpq5 (version 8.4.22-0ubuntu0.10.04.1) will be installed
mutt (version 1.5.20-7ubuntu1.3) will be installed
mysql-common (version 5.1.73-0ubuntu0.10.04.1) will be installed
postfix (version 2.7.0-1ubuntu0.2) will be installed
procmail (version 3.22-18ubuntu1.1) will be installed

E: postfix: subprocess installed post-installation script returned error exit status 75
E: bsd-mailx: dependency problems - leaving unconfigured

无论是Ubuntu还是Fedora，默认都是用的dovecot。